1. Field of the Invention
The technical field of the present invention relates to an aiming system for a fire arm mounted, for example, on an armored vehicle of the type in which the gun can move in elevation and in azimuth following two perpendicular axes.
2. Description of the Prior Art
In the case of a fire arm integrated with the turret of an armored vehicle, the gun is generally carried by a cradle which is trunnioned onto a substantially horizontal axis supported by a mantlet to enable the gun to move in elevation, and the mantlet is itself able to revolve around a substantially vertical axis supported by the chassis of the armored vehicle to allow the gun to move in azimuth.
Such an aiming (sometimes referred to as "laying") system is called elevation aiming within azimuth aiming and is notably described in document DE-A-23 49 720.
When the armored vehicle is standing on perfectly horizontal ground, the elevation trunnion axis of the gun is parallel to the horizontal ground reference plane, and the azimuth bearing axis of the gun is perpendicular to the horizontal ground reference plane.
In practical terms, azimuth aiming of the gun is accomplished by pivoting the turret mantlet around the vertical azimuth axis of rotation.
In the particular event that the armored vehicle is a self-propelled vehicle where the turret has been replaced by a fixed casement inside which the gun has been mounted, azimuth aiming of the gun is generally restricted to plus or minus 10.degree., notably for reasons of safety as regards the crew present in the casement.
In these circumstances, azimuth aiming of the gun is typically accomplished by first aiming the gun by pivoting on the ground the chassis carrying the casement. Thereafter, final accurate azimuth aiming is accomplished by pivoting the gun around the vertical azimuth axis of rotation.
Thus, a system of elevation aiming within azimuth aiming has the disadvantage of limited azimuth aiming when simply rotating the gun of an armored vehicle of the self-propelled type with casemate.